Raina can request service providers to block access to the site under copyright law. If she holds the copyright to the book she wrote, unauthorized posting of her work on a blog constitutes copyright infringement. In many jurisdictions, copyright holders have the right to take action against individuals or entities that reproduce or distribute their work without permission.
In the United States, for example, the Digital Millennium Copyright Act (DMCA) provides a process for copyright holders to notify internet service providers of infringing content and request its removal or blocking. Similar laws exist in other countries, which generally offer copyright holders mechanisms to protect their rights.
Raina should consider sending a takedown notice to the service provider hosting the blog, citing her copyright ownership and the specific infringement. Consulting with a legal professional experienced in intellectual property law may also be advisable to ensure she takes the appropriate steps.